The present invention relates to magnetic head for magnetic recording and/or reproducing and more specifically to a magnetic head configured for greater efficiency in production.
In a magnetic disk apparatus for conducting a magnetic recording/reproducing of a flexible magnetic disk, for example, a magnetic head I shown in FIG. 1 is fitted on a gimbal plate on upper and lower head arms of a carriage. This magnetic head 1 consists of a ceramic slider 2, a core composite 3 formed of a magnetic substance: such as a ferrite, and a coil 4 assembled width the core composite 3.
The core composite 3 is formed by bonding each of cores 3a-3d.
A back core 5, bonded to a lower lateral face of the core composite 3, is fixed to the slider 2. The slider's sliding contact face 2a, which faces a disk, is provided with a slot 2b parallel to the head face. The slider 2 is also provided with a slot 2c opposite-to the lateral face of the core composite 3.
A description of a fabrication process of the slider 2 is given below. 1 A ceramic flat plate is prepared by cutting a ceramic material. 2 A slot for accepting a back core is formed on a face of the ceramic plate. 3 A ferrite bar for use as a back core is prepared by cutting a ferrite material. 4 The ferrite bar is bonded to the slot formed in 2. 5 The topside of the ceramic plate face, which is bonded to the core composite 3, is mirror finished. 6 The aforementioned slot 2c is formed in a ceramic plate face. 7 The ceramic plates is cut along this slot into bars. 8 The aforementioned slot 2b is formed on the surface of the cut ceramic bar, which surface is to be used as a head. 9 The ceramic bar thus provided with the back core 5 and the slots 2b and 2c is cut in the direction at right angles with the longitudinal direction.
The above fabrication process ensures that the slider 2 as shown in FIG. 1 is obtained. This slider 2 is bonded to the core composite 3 as shown in FIG. 2.
FIG. 3 shows the slider 2 bonded to the core composite 3. In FIG. 3, the bottom of the slider 2 and the bottom of the core composite 3 are visible. As shown in FIG. 3, each of extensions 3a.sub.1 -3d.sub.1 of cores 3a-3d is connected to the back core 5 attached to the slider 2. The extensions 3a.sub.1 -3d.sub.1 are portions that extend downward from the cores 3a-3d constituting the core composite 3. Because the extensions 3a.sub.I -3d.sub.1 of the cores 3a-3d are connected to the back core 5, the cores 3a-3d and the back core 5 together form a closed magnetic circuit.
The production of a conventional magnetic head is bound to require ceramic working processes of 1-6 above. It is thus very time-consuming to obtain the slider 2. Therefore, the conventional technology has a disadvantage in that an improvement in an efficiency of the production of the slider 2 is difficult to attain.
Also, the conventional core composite 3 is formed of a magnetic substance such as a ferrite, while the slider 2 is made of a ceramic, which means that the core composite 3 and the slider 2 have different coefficients of thermal expansion. This difference in their thermal expansion accompanies a generation of a stress at a portion at which the core composite 3 and the slider 2 are bonded. This stress creates a strain in the core composite 3. Due to this strain, a magnetic property of the core composite 3 can deteriorate.
A deterioration of the magnetic property of the core composite 3 can sometimes cause phenomena such as this: even when a predetermined amount of current is passed through the coil 4, a magnetic field of a predetermined magnitude is not induced in a gap portion of the core composite 3.